court will be in session since that dramatic ruling last june upholding president obama's health care law. >>> overseas now to afghanistan and a stark reminder tonight of the human cost of war. an attack at a checkpoint left two americans dead, one a serviceman. the 2,000th u.s. military death since the war began. muhammad lila is in the region tonight. >> reporter: some officials are describing this as a firefight between american troops and the very afghan soldiers they were working alongside. for reasons that aren't yet clear it appears as though there were some sort of confrontation at one of the many checkpoints american troops are often stationed at. there was an exchange of gunfire. at first the coalition called it an insider attack at the hands of afghan forces. but later they said the taliban might have been involved. now whatever the reason, the 2,000th american killed in afghanistan is certainly a very grim milestone. this comes just as we are days away from the 11-year anniversary of combat in afghanistan and there is another number to consider, 68,000 american troops are now